Cutting head for comminuting machines

ABSTRACT

A cutting head for comminuting machines, particularly meat cutting machines, includes rotatable angularly displaced knives which are secured to a knife support or driving disk by means of cooperating, or engaging, sets of teeth precluding displacement of the knife in a direction longitudinally thereof relative to their support.

UnitedYStates Patent [191 Karpf [H] v 3,730,363 [451 May 1,1973

[ CUTTING HEAD FOR COMMINUTING MACHINES [75] Inventor: Josef Karpf,Socking-Jungholz,

Germany [73] Assignee: G. W. Steffens, Remscheid, Germany [22] Filed:June 2, 1971 [21] Appl.No.: 149,254

[30] Foreign Application Priority Data June 4, 1970 Germany .....P 20 27429.7

[52] US. Cl. ..24l/282.1 [51] Int. Cl ..B02c 18/00 [58] Field of Search..l46/67-, 106; 24 l 282. 1

[56] References Cited UNITED STATES PATENTS 365,206 6/l887 Stallman .l..I46/67 2,796,102 6/1957 Schmidt, .lr 146/67 X FOREIGN PATENTS ORAPPLICATIONS 594,588 1 1/1947 Great Britain ..l46/67 PrimaryExaminerWillie G. Abercrombie Attorney-Erwin Salzer ABSTRACT A cuttinghead for comminuting machines, particularly meat cutting machines,includes rotatable angu- 'larly displaced knives which are secured to aknife support or driving disk by means of cooperating, or engaging, setsof teeth precluding displacement of the knife in a directionlongitudinally thereof relative to their support.

12 Claims, 11 Drawing Figures PATENTED 3,730,363

SHEET 1 0F 5 JOSEF KARPF Fig PATENTEDM m 3,730.363

SHEET 2 OF 3 v JOSEF KARPF PAIENTEUHAY 1 m5 SHEET 3 OF 3 Fig. 8

2, MW im/m CUTTING HEAD FOR COMMINUTING MACHINES BACKGROUND OF THEINVENTION State of the art comminuting, and particularly meat cutting,machines include rotatable cutting heads provided with cutting kniveswhich are generally angularly displaced and form sets of rotatingknives. The cutting knives are supported by rotatable knive supports, ordriving disks, each supporting one of the rotatable knives. To this endeach driving disk defines a knifereceiving groove extendingsubstantially in the direction of a diameter of a knife support, ordriving disk. The aforementioned groove receives the radially innerportion of a cutting knife, and its cutting portion or blade portionprojects radially outwardly from its radially inner portion and itsknife support, or driving disk. A plurality of such knife supports, ordriving disks, may be stacked and clamped together by appropriateclamping means. The axial spacing between contiguous knife supports, orclamping disks, may be controlled by the insertion of spacers betweensaid supports or disks.

Cutting heads of the aforementioned type project into a bowl containingmeat, or other matter intended to be cut. The capacity of such bowls hasbeen on the increase during recent times, and at the present bowlsadapted to contain as much as 1,300 lbs of meat are not uncommon. Largemachines of this type may have sets of knives having an outer diameterof about 30 inches, and peripheral velocities in the order of, or inexcess of, 300 feet per second. As a result the knives of such machinesare subjected to large forces, in particular large centrifugal forces.It has occured that cutting knives, even though carefully clamped inposition, have moved radially outwardly under the action of centrifugalforces, and have engaged and damaged the surrounding meat or othermatter containing bowl. In such instances there is a likelihood that thecutter knives break. Then the contents of the bowl cannot be used forits intended purpose since the possible presence of particles of cuttingknives in food involves an intolerable danger. The broken end of a knifemay also be ejected and result in injury to personnel operating, orsupervising the operation of, the machine.

In state of the art machines of the kind under consideration it isdifficult to control the angle of displacement of the various cuttingknives. As a general rule, the cutting knives are arranged in groupswhich are angularly displaced, but the constituent knives of each suchgroup are not angularly displaced. This limits the cutting efficiency oftheir cutting heads. It is desirable in the interest of increasedcutting efficiency and in order to obtain comminuted substances whichare as homogenous as possible to angularly displace each cutting kniferelative to any contiguous cuttingknife of a cutting head.

Generally the cross-section of the drive shaft for the cutting head isin the shape of a polygon, e.g. that of a hexagon. It is desirable toform stacks of cutting knives along a drive shaft in the shape of apolygon the position of the constituent-knives of which does not dependupon the geometry of the cross-section of the drive shaft, and whichallow to select an angular displacement of each cutting knive relativeto an adjacent or contiguous cutting knife irrespective of the shape ofthe cross-section-of the drive shaft.

The invention relates to cutting heads which are not subject to theabove referred-to limitations of comparable prior art cutting heads, andinclude the above referred-to desirable features.

SUMMARY OF THE INVENTION A cutting head for comminuting machinesembodying this invention includes a drive shaft, a driving disk and acutting knife. The driving disk is mounted on, and jointly rotatablewith, the drive shaft. It has a knifereceiving groove in one of the endsurfaces thereof. The knife-receiving groove has a first system of teethin one of the lateral surfaces thereof. The cutting knife has a radiallyouter portion and a radially inner portion. The latter defines anaperture for the passage of the aforementioned drive shaft, and isinserted into the knife-receiving groove of the driving disk. An edge ofthe radially inner portion of the cutting knife has a second system ofteeth having substantially the same shape as said first system of teethand engaging said first system of teeth and thereby precludingdisplacement of said cutting knife relative to said driving disk in adirection substantially longitudinally of said groove of said drivingdisk.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a top-plan view of a cuttinghead including a plurality of knives arranged in a predetermined angularrelation;

FIG. 2 is a view of the same kind as FIG. 1 showing a cutting headincluding a plurality of knives arranged in a predetermined angularrelation differing from that shown in FIG. 1;

FIG. 3 is a top-plan view of a cutting knife support exposing to viewthe means for precluding radial movement of a cutting knife;

FIG. 4 is a top-plan view of the cutting knife of the structure of FIG.3 per se turned around deg.;

FIG. 5 shows another embodiment of the invention in the same fashion asFIG. 3;

FIG. 6 shows still another embodiment of the invention in the samefashion as FIGS. 3 and 5;

FIG. 7 shows a spacing disk intended for the structure of FIG. 6;

FIG. 8 is a top-plan view of a modified cutting knife embodying thisinvention; and

FIGS. 9-11, inclusive, are diagrammatic illustrations of variousprofiles of teeth which may be used to carry this invention into effect.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to FIGS. 1 and 2,numeral 1 has been applied to indicate a drive shaft for operating aplurality of rotatable knives 3. The cross-section of drive shaft 1 isin the shape of a hexagon. A plurality of driving disks 2 are mountedupon shaft 1, forming a stack of disks. Each driving disk 2 is providedwith a central aperture or perforation 2a in the shape of a hexagonengaged by shaft 1. The aperture 2a and the cross-section of shaft I arevirtually congruent. Driving disks 2 support cutting knives 3 andtransmit the rotation of shaft 1 to the latter.

The shape of knives 3 and their relative arrangement may vary. As shownin FIG. 1, knives 3 form three separate and distinct groups. The knivesforming an upper right group have a smaller angular displacement thanthe knives forming an upper left group and the knives forming a lowercenter group. According to FIG. 2 the angular displacement of all knives3 is equal and 30.

In the embodiment of the invention shown in FIGS. 3 and 4 driving disk 2supports a pair of radially spaced fastener segments 2b. The radiallyinner surfaces 2c of fastener segments 2b define a groove 2' forreceiving the radially inner portions or shafts 3a of knives 3. Thefastener segments 2b are positioned relative to, and secured to, drivingdisks 2 by pins 2d and screws 2e. This makes it possible to readilyremove and replace fastener segments 2b. This mode of affixing fastenersegments 2b to driving disks 2 is, however, optional. Fastener segments2b may be permanently affixed to driving disks 2, as by welding orrivetting. As shown in FIG. 3 the radially inner surface 20 of the upperfastener segment 2b is sawtooth-shaped, as indicated at 2f, but theradially inner surface 20 of the lower fastener segment 2b is planar.

Knife 3 is provided at the radially inner portion 3a thereof with anelongated hole or aperture 3b having a width x. The width x exceeds thelargest diameter y of drive shaft 1. The parallel edges of the radiallyinner portion 3a of knives 3 are provided with systems of teeth 3c whichhave the same shape as the teeth 2f on fastener segment 2b. As shown inFIG. 3, the upper system of teeth 30 of knife 3 engages the system ofteeth 2f of the upper fastener segment 2b, and thus firmly positionsknife 3, while the lower system of teeth 30 of knife 3 engages theplanar surface 2c of the lower fastener segment 2b. The upper system ofteeth 3c and the lower system of teeth 3c of knife 3 are displaced inlongitudinal direction half the length of one tooth.

FIG. 3 shows a position of knife 3 in solid lines and a position ofknife 3 in dotted lines. Assuming the length of a tooth to be in theorder of one-tenth of an inch, and assuming that a knife that hasoriginally been positioned as shown in solid lines in FIG. 3 is placedupon having been sharpened by grinding in the position shown in dottedlines in FIG. 3, this would amount to a shortening of the effectivelength of the knife of but one half the length ofa tooth, or aboutone-twentieth of an inch.

In addition to the two fastener segments 2f provided on the frontsurface of driving disk 2 the same may be provided with a pair offastener segments 2fon the rear side thereof, thus forming aknife-receiving groove 2 both on the front and on the rear side thereof.A knife is then arranged in each of the knife-receiving grooves 2 ofwhich one has the position indicated in solid lines of FIG. 3, and theother the position indicated in dotted lines in FIG. 3. Both knivesrotate in parallel planes which are spaced in a direction longitudinallyof drive shaft 1. A cross-section through this arrangement would besubstantially in the shape of an I.

Referring now to FIG. 5 showing another embodiment of the invention, thedriving disk 2 of the cutting head defines a groove 2" receiving twoknives 3'. The radially inner fork-shaped portion 3a of each knife 3'has a projection 3d whose radially outer edge forms a system of teeth3c. Each of the teeth 30 has the shape of an equilateral triangle. Theradially inner edges 3e of each projection 3d is straight and planar,i.e., doesnot have a toothed surface. The bottom of groove 2" isprovided with a pair of fastener blocks 3] which may be pinned to, andscrewed against, driving disk 2 in the same fashion as the fastenersegments 2b of FIG. 3.

The left side and the right side of FIG. 5 illustrate two slightlydifferent modifications of the same structure, as will be explainedbelow more in detail. As shown to the left of FIG. 5, the portion 3g ofknife 3 has a planar surface arranged in abutting relation to a planarsurface of fastener block 3]. As shown to the right of FIG. 5, theportion 3g of knife 3 has a toothed surface engaging a similar toothedsurface of fastener block 3)". The arrangement shown to the left of FIG.5 is satisfactory, but that shown to the right of FIG. 5 provides aneven more effective mode of positioning knife 3.

Referring now to FIG. 6, drive shaft 1" supports the driving disk 2".The cross-section of shaft 1 is hexagonal and driving disk 2" has acorresponding centrally located hole or aperture. Each of a pair ofknives 3" is provided with a radially inner or shaft portion 3a". Thefastener segments 2b" and one end surface of driving disk 2" form agroove or recess 2" for receiving the radially inner ends of knives 3".Each knife is provided with a pair of oblong holes 3h at the radiallyinner end thereof. Screws 3i" projecting through the oblong holes 3hfirmly secure the knives 3" to driving disk 2". The radially innerportions 3a of knives 3" are provided with systems of teeth 30" engagingcorresponding systems of teeth 2f" provided in the lateral surfaces 20"of fastener segments 2b".

Upon securing the knives 3" to driving disk 2" a spacer disk 4 shown inFIG. 7 is superimposed upon parts 3 and 2". The spacer disk 4 isprovided with four apertures or holes 4a in registry with screws 31" forreceiving the heads of the aforementioned screws or for receiving nutsmounted upon the aforementioned screws. The spacer disk 4 is furtherprovided with a central bore or aperture 4b having a larger diameterthan the largest diameter of shaft 1 Referring now to FIG. 8, thisfigure shows a cutting knife 3" having a radially inner portion 3a,having about the same dimensions, or the same diameter, as the diameterof a shaft-driven driving disk (not shown in FIG. 8). The radially innerportion of knife 3" supports a plate member 3k which may be affixed toknife 3" by means of rivets 31". The plate member 3k is provided with anoblong aperture 3b which may be in the shape of a hexagon, as shown inFIG. 8. The width of oblong aperture 3b exceeds the largest diameter ofthe driving shaft (not shown in FIG. 8) intended to rotate knife 3".Knife 3" is provided with a hole or aperture which is substantiallycongruent, and arranged in registry with, the hole or aperture 312" inplate member 3k, and which, therefore, does not appear in FIG. 8. Theplate member 3 k is provided with a pair of parallel edges each having asystem of teeth 3c. These teeth 3c' are intended to be engaged by a pairof fastener segments of the kind shown and described in connection withFIG. 3 of which one or both have a system of teeth on juxtaposedsurfaces thereof.

The system of teeth shown in FIG. 9 is substantially sinusoidal, thatshown in FIG. 10 has teeth which have the shape of trapezoids, and thatshown in FIG. 11 has teeth which are rectangular.

As shown in FIGS. 1 and 2 it may be necessary or desirable to arrangethe constituent knives of the cutting head in different configurations,in particular to vary the angular displacement thereof as required forany particular application. This makes it necessary to vary the angularrelation between the median line of the knife-receiving groove in thedriving disks (the line M-M of FIG. 3) and the holes or apertures in thedriving disks (marked in FIG. 3) for mounting the latter on the driveshaft. There are two ways of achieving the desired end. All of aplurality of driving disks may be provided with pairs of fastenersegments of which each is arranged in the same position. Thereupondriveshaft-receiving holes are punched out of the driving disks in anyparticular angular relation which may be desired. As an alternative, allof a plurality of driving disks may be provided withdriving-shaft-receiving holes, or apertures, which have the sameposition, and thereafter fastener segments may be mounted on the drivingdisks which are angularly displaced as deemed necessary, or desirable.

It will be apparent from the above that in all embodiments of theinvention the cutting knives are positively blocked against movement inany radial direction under the action of centrifugal forces by virtue ofpairs of co-engaging sets of teeth. The shape of the co-engaging teethis optional, as suggested by FIGS. 9 to 11, i.e. the desired result maybe achieved with teeth of various shapes. The shape of the teeth shownin FIGS. 3 and 4 is substantially the shape of the teeth of a saw madeup of triangles whose sides are of unequal length enclosing an acuteangle at the point farthest remote from the center line, or median line,of the knife blade. The length of each tooth is preferably in the orderof onetenth of an inch, or slightly more than that. It has been founddesirable to minimize the spacing of the radially outer ends of thecutting knives from the wall of the container or bowl receiving thecutting head. This can be achieved readily with the structuresillustrated and described. It will be apparent from the above that thedrive shaft does not engage the sidewalls of the oblong apertures in theradially inner portions of the cutting knives, and does not directlytransmit its torque to the cutting knives. The drive shaft engages asubstantially congruent aperture in the driving disks and drives thelatter, and the driving disks transmit a torque to the cutting kniveswhich they support. The oblong aperture for the passage of the driveshaft may be a hole, as shown in FIGS. 1 to 4, or the radially inner endof the cutting knives may be forked-shaped, in which case the oblongaperture in the radially inner ends of the cutting knives is in the formofa slot which is open on one side thereof as shown in FIG. 5. Thestructure of FIG. 8

makes it possible to impart to the radially inner portion of the cuttingknives a particularly large diameter which may be desirable in theinterest of increased mechanical strength.

As explained above it is desirable to displace the two lines of teeth ofa cutting knife slightly in a direction longitudinally thereof. As analternative which is equivalent, a blade-receiving groove in drivingdisks may be provided on opposite lateral surfaces with rows ofteethwhich are displaced relative to each other in a direction longitudinallyof the cutting knife, the displacement being preferably half the lengthof a single tooth.

I claim as my invention:

l. A cutting head for comminuting machines including a. a drive shaft;

b. a driving disk mounted on and jointly rotatable with said drive shaftand having a knife-receiving groove in one of the end surfaces thereof,said knife-receiving groove having a first system of teeth in one of thelateral surfaces thereof; and

. a cutting knife having a radially outer portion and a radially innerportion, said radially inner portion defining an aperture for thepassage of said drive shaft and being inserted into said knife-receivinggroove of said driving disk, an edge of said radially inner portion ofsaid cutting knife having a second system of teeth having substantiallythe same shape as said first system of teeth and engaging said firstsystem of teeth and thereby precluding displacement of said cuttingknife relative to said driving disk in a direction substantiallylongitudinally of said groove of said driving disk.

2. A cutting head as specified in claim 1 wherein said driving disk isprovided with a pair of groove-forming fastener segments, one of saidpair of fastener segments having said first system of teeth on theradially inner edge thereof engaging said second system of teeth on anedge of said cutting knife.

3. A cutting head as specified in claim ll including a. a driving diskhaving a pair of knife-receiving grooves each on one of the end surfacesthereof, each of said pair of knife-receiving grooves having a firstsystem of teeth in one of the lateral surfaces thereof; and

b. a pair of cutting knives each inserted into one of said pair ofknife-receiving grooves and each having a second system of teethengaging said first system of teeth in one of the lateral surfaces inone of said pair of knife-receiving grooves.

41. A cutting head as specified in claim ll wherein said knife-receivinggroove is provided with teeth in both lateral surfaces thereof, theteeth in one of said surfaces being displaced relative to the teeth inthe other of said surfaces in a direction longitudinally of said cuttingknife.

5. A cutting head as specified in claim 1 wherein opposite edges of saidradially inner portion of said cutting knife each have a second systemof teeth, the teeth on one of said opposite edges being displacedrelative to the teeth on the other of said opposite edges in a directionlongitudinally of said cutting knife.

6. A cutting head as specified in claim 4 wherein the teeth on one sideof said opposite edges are displaced relative to the teeth on the otherof said opposite edges about one half the length of one of said teeth.

7. A cutting head as specified in claim ll wherein said drive shaft hasa cross-section in the shape of a polygon, and wherein the said apertureof said cutting knife is oblong and has a width in excess of the largestdiameter of said polygon.

8. A cutting head as specified in claim 1 including a. a plurality ofstacked driving disks each having a central aperture in the shape of aregular polygon angularly displaced relative to an aperture in acontiguous of said plurality of stacked driving disks; and

b. a plurality of angularly displaced cutting knives each supported byone of said plurality of driving disks.

9. A cutting head as specified in claim 1 wherein said radially innerportion of said cutting knife is substantially fork-shaped and has arelatively long radially outer prong and a relatively short radiallyinner prong, a radially outer edge of said relatively long prong havingsaid second system of teeth and an edge of said relatively short prongbeing engaged by a clamping block solid with said driving disk.

10. A cutting head as specified in claim 8 wherein juxtaposed edges ofsaid relatively short prong and of said clamping block are provided withcooperating auxiliary teeth.

11. A cutting head as specified in claim 1 wherein said second system ofteeth is provided on an edge portion of a plate member abutting againstsaid radially inner portion of said cutting knife, being solid with saidcutting knife and having an aperture for the passage of said driveshaft.

12. A cutting head as specified in claim 11 wherein said plate memberhas a pair of parallel edges each provided with teeth arranged to engagecooperating teeth solid with said driving disk.

1. A cutting head for comminuting machines including a. a drive shaft;b. a driving disk mounted on and jointly rotatable with said drive shaftand having a knife-receiving groove in one of the end surfaces thereof,said knife-receiving groove having a first system of teeth in one of thelateral surfaces thereof; and c. a cutting knife having a radially outerportion and a radially inner portion, said radially inner portiondefining an aperture for the passage of said drive shaft and beinginserted into said knife-receiving groove of said driving disk, an edgeof said radially inner portion of said cutting knife having a secondsystem of teeth having substantially the same shape as said first systemof teeth and engaging said first system of teeth and thereby precludingdisplacement of said cutting knife relative to said driving disk in adirection substantially longitudinally of said groove of said drivingdisk.
 2. A cutting head as specified in claim 1 wherein said drivingdisk is provided with a pair of groove-forming fastener segments, one ofsaid pair of fastener segments having said first system of teeth on theradially inner edge thereof engaging said second system of teeth on anedge of said cutting knife.
 3. A cutting head as specified in claim 1including a. a driving disk having a pair of knife-receiving grooveseach on one of the end surfaces thereof, each of said pair ofknife-receiving grooves having a first system of teeth in one of thelateral surfaces thereof; and b. a pair of cutting knives each insertedinto one of said pair of knife-receiving groOves and each having asecond system of teeth engaging said first system of teeth in one of thelateral surfaces in one of said pair of knife-receiving grooves.
 4. Acutting head as specified in claim 1 wherein said knife-receiving grooveis provided with teeth in both lateral surfaces thereof, the teeth inone of said surfaces being displaced relative to the teeth in the otherof said surfaces in a direction longitudinally of said cutting knife. 5.A cutting head as specified in claim 1 wherein opposite edges of saidradially inner portion of said cutting knife each have a second systemof teeth, the teeth on one of said opposite edges being displacedrelative to the teeth on the other of said opposite edges in a directionlongitudinally of said cutting knife.
 6. A cutting head as specified inclaim 4 wherein the teeth on one side of said opposite edges aredisplaced relative to the teeth on the other of said opposite edgesabout one half the length of one of said teeth.
 7. A cutting head asspecified in claim 1 wherein said drive shaft has a cross-section in theshape of a polygon, and wherein the said aperture of said cutting knifeis oblong and has a width in excess of the largest diameter of saidpolygon.
 8. A cutting head as specified in claim 1 including a. aplurality of stacked driving disks each having a central aperture in theshape of a regular polygon angularly displaced relative to an aperturein a contiguous of said plurality of stacked driving disks; and b. aplurality of angularly displaced cutting knives each supported by one ofsaid plurality of driving disks.
 9. A cutting head as specified in claim1 wherein said radially inner portion of said cutting knife issubstantially fork-shaped and has a relatively long radially outer prongand a relatively short radially inner prong, a radially outer edge ofsaid relatively long prong having said second system of teeth and anedge of said relatively short prong being engaged by a clamping blocksolid with said driving disk.
 10. A cutting head as specified in claim 8wherein juxtaposed edges of said relatively short prong and of saidclamping block are provided with cooperating auxiliary teeth.
 11. Acutting head as specified in claim 1 wherein said second system of teethis provided on an edge portion of a plate member abutting against saidradially inner portion of said cutting knife, being solid with saidcutting knife and having an aperture for the passage of said driveshaft.
 12. A cutting head as specified in claim 11 wherein said platemember has a pair of parallel edges each provided with teeth arranged toengage cooperating teeth solid with said driving disk.